Polymeric biguanides have been known for some time to have antibacterial and antifungal properties. More recently, such materials have been found to be useful in not only preventing the growth of bacteria and fungi but to be effective in controlling the growth of algae in swimming pool water. These materials are currently being presented to the pool operator as a safer and more effective alternative to the use of chlorine in sanitizing recreational pool water.
The use of disinfecting or sanitizing materials such as chlorine and biguanides requires that safe and effective concentration levels be maintained in the host fluids. The usual method for doing this involves routinely taking a sample of such fluid and subjecting it to an accepted testing procedure. Laboratory testing is the best possible alternative; however, home owners and swimming pool maintenance personnel usually do not have access to laboratories and must rely on a field test. The present field tests for biguanide concentration levels in swimming pool water involve a liquid test kit which requires that a representative sample of water be taken from the pool and drops of the liquid reagent be added thereto. Any change in the color of the water sample is then compared to a color chart or color comparator and the concentration level of the biguanide in the water is calculated. The present liquid drop tests are difficult to use and read and, for the most part, are not sufficiently accurate.